Self compensated motor fuel and process of making same



Oct. 9, 1934. Q ELLIS SELF COMPENSATED MOTOR FUEL AND PROCESS OF MAKING SAME Original Filed April 29, 1924 aumzuozou gwym'vtoz [AKLETDN ELM-S Q 53: En

Patented Oct. 9, 1934 "PATENT OFFICE I SELF COMPENSATED MOTOR FUEL AND PROCESS OF MAKING SAME Carleton Ellis, Montclain'N. J., assignor to Ellis- Foster Company, a corporation of New Jersey I Application April 29, 1924, Serial No. 709,915

Renewed July 2, 1932 cnm- (01. 196-142) This invention relates to a self-adiusted motor fuel containing self-made correctives of combustion disturbances and to the process of making same and relates especially to a pressure- 6 cracked modified motor fuel having desirable characteristics.

This application is a continuation in part of my co-pending cases Serial Nos. 703,980 and 705,935. This application is also a continuation in part of application Serial Number 538,338 filed February 21, 1922. I

The invention has for one object the production of a modified gasoline or gasoline-substitute relatively free from those objectionable qualities such as knocking which now interfere with the proper utilization of ordinary gasoline and which call for the addition of foreign substances as remedies; such as lead and tin ethyl compounds, iodine, or various other so-called tonics and palliatives' 1 According to the present invention ordinary gasoline or preferably gasoline made by a cracking operation preferably under high pressure may be caused to acquire such a constitution or composition by appropriate treatment that the addition of metal dopes or tonics is unnecessary; in other words that the composite character of gasoline aifords within itself the potential material for correction of its defects without resorting to foreign substances, which in many cases doubtless are capable .of producing unpleasant side reactions, poisonous effects e c. a More specificially the invention relates to a motor fuel comprising cracked gasoline containing substances causing engine-knock and ther molytically-cyclicized bodies of petroleum origin tending to engine knock and oxidized bodies also of petroleum origin, the proportion of such cyclicized and oxidized bodies being predetermined for the purpose and with the result of reducing engine-knock to a considerable degree. Or stated in another way the invention concerns a self-adjusted motor fuel comprising cracked gasoline containing heavy ends productive of engine-knock and including an influential proportion of petroleum-generated thermolytically-cyclicized bodies and oxygencontaining compounds of petroleum origin; said bodies and compounds beingproportioned in a predetermined manner for the purpose and with the result of minimizing engine knock. The invention also .embraces. the processof producing a self-adjusted motor fuel comprising cracked gasoline containing heavy ends productive of engine-knock and including an influential proportion of petroleum-generated thermolytically-cyclicized bodies and oxygen-containing compounds of petroleum origin; said bodies and compounds being proportioned in a predeter- 69 mined manner for the purpose and with the result of minimizing engine knock to a considerable degree, said fuel preferably having a boiling range from about 130 F. to 450 F.

The drawing illustrates diagrammatically in Figure l, a form of plant that may be used in connection with this invention; and in Figure 2 a fragmentary portion of this plant showing a modification thereof.

An oil which is considerably heavier than gasoline as for example gas oil is warmed or preheated by means of a heat exchanger and the preheated oil is passed by means of a force pump into and through a long coil of pipe placed over a strong fire so that the oil "in passing through the coil will be heated to a temperature of say between 700 and 900 7E2, a temperature of 800 F. being satisfactory. The oil discharges from the coil into a soaking tank preferably situated above the coil so that the heat from the fire which is unabsorbed by thecoil will supply additional heat to the soaking tank. The apparatus is maintained under a pressure preferably of between 250 and 350 pounds above atmospheric pressure. If desired also a small proportion of air may be admitted with-the oil at the force pump or air may be forced into the soaking tank to bring about a, partial or initial oxidation. This serves to raise the temperature more rapidly, helps to build up an initial pressure and has a beneficial action in some cases on oils containing sulphur. The strong heating in the coil and the further digestion-of the oil in the soaking tank under pressure results in a high yield of gasoline and kerosene. 95

The vapors or cracked distillation products coming from the soaking tank or other cracking apparatus preferably are oxidized soon after withdrawal from such cracking apparatus while thevapors are still hot enough to react readily with air or oxygen either with or without the aid of catalytic material. By utilizing the gases at a temperature approaching that employed in the cracking step it does not become necessary to employ special heating devices and to use additional fuel for the purpose. The reaction with the air or oxygen or other oxidizing gas is exothermic and heat is therefore developed which may be utilized by passing the vapors through a heat-exchanger wherein raw oil employed in the oxidizing step.

The oxidation may be carried out by simply, admitting air at one or more points in a flue or chamber through which the vaporized disti-llate is passing; the temperature at this point being such that a substantial utilization of the oxygen takes place. Preferably the air is admitted at a plurality of points along such flue or conduit. In this conduit there may be. situateda bed of catalytic material suchas fragments of iron coated with vanadium oxide, granular alumin'umcoated with a mixture of molybdenum and vanadium oxide or other appropriate. catalytic material preferably in-a loose granular form, allowing the vapors and gases to pass through readily. In other cases metallic gauze, wire or balls, fragments of pumice, quartz, fire brick or other refractory material may be placed in the oxidizing flue or fiues. The latter preferably are set vertically with the vapor and gas mixture passing downward therethrough and being drawn'oif at the bottom to.

condensers. The condensation may take place at atmospheric pressure if desired although pref erably ,such condensation is carried out at pressures aboye atmospheric. Between the oxidizing fiuesjor chamber and the condensers there may be: placed dephlegmators or heat-exchangers as desired. The dephlegmators may discharge their heavy portion back into the.

cracking. apparatus. A battery of cracking apparatus with a centralized oxidizing chamber may be used in some cases especially when the arrangement is such that the drop in temperature is not prejudicial.

The cracking apparatus preferably as noted is intended to operate under a pressure of from 250 to 350 pounds above atmospheric pressure.

In general I prefer as stated in Serial 523,208

now U. S. Patent 1,516,720, to use a pressure of at least 10 atmospheres and preferably between 10 or 20 .atmospheres or higher according to conditions;

Insome cases the steps both of cracking and oxidizing may be carried out in the vapor phase at atmospheric pressure or at pressures above atmospheric for example at four or fiveatmospheres. Another modification is that of causing the cracking to take place at atmospheric pressure and oxidation to progress at a higher pressure. Again the procedure may 'be carried out in a reverse way, that is cracking is effected 5 at a pressure above atmospheric and oxidation 5 is conducted at atmospheric pressure. B conducting as separate steps the opera on of cracking and that ofoxidizing it is possible to have differential pressures best adapted for the, particular operation in hand.

Pressures below atmospheric are not precluded in either step but are not recommended.

When cracking and condensation are together carried out under approximately the same pressure e. g. three or four atmospheres above atmospheric pressure the oxidation phase may be conducted at any point in the condenser line at such a distance from the cracking coil,

tank or still that a suitable temperature exists which may'tend' to direct the reaction toward the particular type of oxidation or mixed oxidation desired. -Forexample there maybe various reactions'suchas those of hydroxylation, formation of ethylene' oxide and higher oxides, aldehydes, aliphatic, and aromatic acids, ketones, keto-aldehydes, keto-acids, keto-alcohols, aldehyde-acids, aldehyde-alcohols, alcohol acids etc. In so complicated a mixture as that of cracked oil it of course not possible to provide conditions whicl'i'will produce any one compound or restricted type of compounds exclu- -sive1y but conditions may be directed to yield an influential amount of a specified compound or group of related compounds in some cases.

When cracking takes place under considera-ble pressure and. condensation is at a substan t ially lower pressure or is in the neighborhood of atmospheric 'pressure the oxidizing chamber may be under. the pressure exerted in the still or crackingchamber or it may be under the pressure of the condenser line. Or two or more oxidizing chambers may be used in series, one or morebeing operated at approximately still pressure and others being at about condenser pressure.

In this way, separate or differential oxidations may take, place under different temperatures and pressures. This may become a matter of: importance in the treatment of a complex mixtureof; saturated and unsaturated hydrocarbons, aromatic, naphthenic and paraffin bodies and other complex substances which may be present in the cracked material.

Thus oxidation may take place at one or more places after'the oil has been cracked. In addition there may b fl-S' noted a certain amount of oxidation provided inthe heating coil of the cracking apparatus or in the soaking tank.- I

Oxyg nmay be admitted at any or allof these point Preferably however I prefer to carry out the oxidation in the vapors themselves and therefore preferably after leaving the soaking tank because at this stage-the temperature of oxidation is under better control. In the heating coil and soaking tank the temperature necessarily must be 'that required to produce crackedggasoline by which term I mean gasoline produced by the cracking operation. The temperature must favor cracking and not necessarily oxidation. ,By' carrying out the oxidation as a separate step the temperature can be adjusted to bring about the most efficient conditions of oxidation to produce intermediate products assisting in the adjustment 'of the motor fuelpto. render the highest and most effective development ofpower when employed in an internal combustion engine.

The temperature at which the oxidation is carried out in the case of the cracked vapors is preferably above'250 F. and preferably not in no to use a temperature which is below that of red- 5 ness but -is at a black heat at which oxidation progresses effectively without the formation of any excessive amount of ultimate products of combustion. Such procedure has been indicated in Serial 284,372 now U. s. Patent 1,697,267.150-

Thus by proceeding in this manner oxidation may be carried out at a temperature independent of the cracking temperature. A more gentle oxidation may be carried out at temperatures below 400 F. Under these circumstances a special orientation of oxidation may be effected. Temperatures between 250 F. and 400 F. may be employed when the object primarily is that of yielding'motor fuels of reduced smoke-forming tendencies and a lower carbonizing effect on engine cylinders.

In this connection it may be noted that those bodies which produce smoky flames or are recognized in the gas industry as illuminants including the ethylenes and other substances oxidize with relative ease.. These may be converted by gentle oxidation to partial or intermediate combustion products and a diminution in carbon deposition in engine cylinders may be expected when the fuel is employed. for the generation of power by means of internal combustion engines.

When a mild or moderate oxidation is carried out at say temperatures whose'lower range is 350 F. or 375 F. and whose upper range is preferably not in excess of 450 F. or 475 F. that is a spread of approximately 100 whose upper limit preferably does not exceed that mentioned, it is generally desirable to avoid exposing the oxidized material to higher temperatures for the reason that reactions may take place which would be prejudicial for the purpose in hand. Thus a reaction between oxidized material and a hydrocarbon could take place as follows:

as possible or even slightly lower the temperature as oxygen compounds accumulate in the zone of reaction.

If the heat development in the oxidizing f'lues becomes too great the temperature may be reduced by cooling coils and the excess heat may be employed to advantage in preheating the raw oil.

The rate and character of oxidation is modified by pressure. Combustion under pressure is more vigorous and therefore requires more adequate control. Partial combustion giving intermediate products of mildoxidation may at ordinaryatmospheric pressure develop so little heat as to fail to be self-sustaining while at a pressure of several atmospheres self-sustaining heat conditions may result or the heat development may become excessive and clell for cooling.

The oxidation of pet oleum oil and especially cracked material containing illuminants under superatmospheric pressure for example a pressure say of three or four atmospheres above atmospheric, on the one hand, up to ten or twenty atmospheres or even higher pressures isa feature included within the preferred form of the invention.

Another feature of importance is that of admitting air or oxygen in such quantities and under such conditions that explosive mixtures are not produced. An excess of air in such an amount to cause explosions should not be employed and preferably only a comparatively small proportion of the cracked gasoline vapors need to be oxidized in order to obtain a. fuel of the desired qualities. Thus while the whole body of vapors from the soaking tank, other than that portion which has been removed by dephlegmation, may be passed through the oxidizing zone with a moderate amount of air preferably introduced at a series of places to avoid any localzed combustion and explosion, only a small amount of such vapors, say 5 or 10 per cent need to be actually oxidized and if the conditions are such that the air is admitted in a uniform and well-distributed manner the combustion of the more sensitive or more easily oxidized substances present may take place resulting in a more stable form of motor fuel. It is well known that cracked gasoline contains various substances which may be of the acetylene type or conjugated dioleflns or bodies possibly of the nature of cyclodienes which resinify easily and such gum formation occurring in the finished gasoline gives rise to trouble. In one form of my invention it is an object to carry out the oxidation in sowell-regulated a manner that these sensitive bodies may become oxidized and instead of detracting from the quality of the fuel by forming gummy deposits therein at some subsequent time I propose to ut'lize these bodies in an oxidized form to assist in reducing engine knock and to diminish the tendency to formation of carbon (1613081139111 the engine cylinders.

The crude motor fuel collected by condensation may contain too large an amount of heavy ends that is kerosene and other bodies and preferably is submitted to distillation to obtain an oxidized naphtha boiling from say 100 F-to 450 F. Another boiling range is between 130 F.-440 F. It is one object of the present invention to employ a somewhat'higher proportion of heavier ends, that is kerosene or oxidized kerosene than is feasible in a motor fuel which is not of the self-adjusted type. Hence I may in some cases employ a boiling range which extends up to 500 F. or thereabouts. The initial boiling point may vary considerably depending upon whether the motor fuel is to be used in summer or winter weather, lighter boiling constituents being desired in the latter case. In any case the boiling range preferably should not 'extend'above 500 F. In-the summer season a motor fuel containing a larger proportion of oxidized kerosene, say up to 30 per cent or so may be employed while in the winter season a lesser amount of kerosene is desirable. ing the winter season the consumption of kerosene for other purposes is greater hence adjustment made in this manner is quite feasible from a commercial standpoint.

The crude oxidized naptha obtained in this manner may be used without refining in some cases or it may be treated with concentrated or diluted sulphuric acid followed by caustic soda treatment and if desired by the doctor treat-' ment. Hypochlorous acid or hypochloritesma be used for refining in some cases. From the foregoing it will be noted that the oxidation of the vapors is not limited to a catalytic process. The process of the present invention also comprises cracking a heavy oil such as gas oil under a pressure of' at least 10 atmospheres above atmospheric pressure and admixing some portion at least of the products of cracking, prior to cooling below areactive Durtemperature, with air insumcient in amount to form an explosive mixture. In one form of faction of air and the nitrogen separated may be employed to-make synthetic ammonia by catalytic combination with hydrogen derived from still gases in the manner recited in certain of my copending applications.

Adensed without oxidation may have to be vapor-' When air is directly employed for oxidation, or when a mixture of air and stack gases is used the uncondensed gases liberated from the condensers may be superheated or cracked at a high temperature to obtain an impure mixture of nitrogen and hydrogen which may be purified and employed in making synthetic ammonia.

Furthermore it may be noted that the reactions resulting from adding cold air to very hot cracked vapors may be quite difierent from those occurring when the vapors at a lower temperature are mixed with preheated air; the latter for example being admitted at the same temperature as the vapors. Thus the treatment ,tion in the orientation of desired reactions.

There may be circumstances furthermore when cracked gasoline which has been conized and oxidized in accordance with-the foregoing. Purification to remove sulphur [may be may go on at the temperature maintained in the oxidation-zonewhen oxidation isycarried out in the vapor phase as a step separate from that of cracking The degreebf cracking ordinarily is of *an incidental character as the period of exposure to oxidizing conditions outside of the cracking still is normally brief-in comparison with the period of treatment glven to the oil in the cracking step'proper. 'Thus while'the treatment of a charge 01.. onto crack itmayrequire a considerable number of hoursthe vapors leaving the cracking still m pass through -'an oxidizing zone wherein they are exposed to the action of an o en-containing gas for a period of only a few onds or a few minutes. The action of oxidation generally speaking isconsiderably accelerated and to some extent oriented by the use of catalyzers.

The foregoing procedure of cracking under pressure and oxidizing results in modifying the resulting motor fuel by supplying cyclic bodies such as benzol and other aromatic hydrocarbons and various other cyclic substances and oxidized products thereby affording a self-adjustment of the composition of the motor fuel to supply correctives of combustion disturbances in the operation of internal combustion engines. I may add that should it be desired to carry out oxidation of the vapors at a stage in the operation where the temperature has been reduced below that at which oxidation readily occurs my invention does not preclude the heating of the product which is to undergo oxidation to a temperature sufllcient to put this into effect. In some cases it may be necessary or desirable to preheat the air or other oxidizing gas employed to supply oxygen for the oxidizing step.

In the apparatus illustrated diagrammatically in Figure 1, for carrying out the invention, there is shown on oil inlet 1 from which oil is fed to a heat exchanger 2,- where it may be pre-heated prior to its entry to the heating coil. A pump 3 may be used to force the oil through the heating coil 4, the heating coil being heated by a furnace 5 to the desired temperature. An air inlet 6 may be used for injecting air into the preheated oil. From the heating coil 4 the oil passes to a soaking tank 7, into which air may be injected through the air inlet pipe 8. A

valve 20 in the pipe 4 may be used to control the passage of the oil from the oil 4 into the tank 'I. From the soaking tank the vapors and gases pass through a pipe 9 having ,a control valve '21; to a dephlegmator 10, in

which tars and heavy matter may be removed as through the draw-off line 11. From the dephlegmator or other separator, the vapors and gases pass from the upper portion of the dephlegmator through conduit 10' controlled by valve 23, to the oxidation chamber 12. An air inlet pipe 13 serves to; admit air to the oxidation chamber. From the latter, the oxidation material passes through pipe 14 controlled by valve 24, to the heat exchanger 2, where these vapors and gases, etc. serve to preheat the inl coming oil. From the heat exchanger the oxidation products pm to a condenser 15, a valve control 25 serving to control the passage of the oxidation products into the condenser 15. Condensed material is collected in a trap or collector 12 5 16, any residual products passing from the collector 16 by pipe 1'1, controlled by valve 26.

Figure '2 illustrates a portion of this plant when the separation of heavier material is not made, the vapors and gases passing directly from the'soaking tank through pipe 9' to the oxidation chamber. In this form of apparatus, the oil from the pipe 4' passesinto the soaking tank 7',anairinlet8'servingtoadmitairtothe soaking tank. From the tank; the va-- pors and gases pass through the pipe 9' controlled by valve-22, to the oxidation chamber 13' provided with an air inlet pipe 13', and an outlet 14' for the oxidation material.

Valves 20, 21, 22, 2 3, '24, 25, and 26 shownon the drawing, enable the pressures and temperatures maintaineddn particular portions of the apparatus to becontrolled.

What I claim is:- v 1 '1. A cracked motor spirit of petroleum origin comprising products of gentle oxidation between 250 F. and 475 F. a

2. The process which comprises cracking petroleum oil under a pressure above atmospheric, 150

conveying a portion at least of the cracked products under pressure through an oxidizing zone, admitting air in regulated amount to said oxidizing zone and maintaining the temperature I below 475 F. but above 250 F.

3. The process which comprises cracking petroleum oil under a pressure above atmospheric,

conveying a portion at least of the cracked products under pressure substantially in' excess of 10 atmospheres through an oxidizing zone, admitting air in regulated amount to said oxidizing zone and maintaining the temperature below 475 F. but above 250 F.

4. The process which comprises cracking petroleum oil under a pressure above atmospheric,

zone, admitting oxygen in regulated amount to v said oxidizing zone and maintaining the temperature below 475 F. but above 250 F.

CARLETON ELLIS. 

